<template>
  <div v-bind="fullScreenParentProps">
    <a-icon v-if="fullScreen" class="full-screen-icon" :type="iconType" @click="()=>fullCoder=!fullCoder" />

    <div class="code-editor-cust full-screen-child">
      <textarea ref="textarea"></textarea>
      <span @click="nullTipClick" class="null-tip" :class="{'null-tip-hidden':hasCode}" :style="nullTipStyle">{{ placeholderShow }}</span>
      <template v-if="languageChange">
        <a-select v-model="mode" size="small" class="code-mode-select" @change="changeMode" placeholder="请选择主题">
          <a-select-option
            v-for="mode in modes"
            :key="mode.value"
            :value="mode.value">
            {{ mode.label }}
          </a-select-option>
        </a-select>
      </template>

    </div>
  </div>
</template>

<script type="text/ecmascript-6">
// 引入全局实例
import _CodeMirror from 'codemirror'

// 核心样式
import 'codemirror/lib/codemirror.css'
// 引入主题后还需要在 options 中指定主题才会生效 darcula  gruvbox-dark hopscotch  monokai
import 'codemirror/theme/panda-syntax.css'
//提示css
import 'codemirror/addon/hint/show-hint.css'

// 需要引入具体的语法高亮库才会有对应的语法高亮效果
// codemirror 官方其实支持通过 /addon/mode/loadmode.js 和 /mode/meta.js 来实现动态加载对应语法高亮库
// 但 vue 貌似没有无法在实例初始化后再动态加载对应 JS ，所以此处才把对应的 JS 提前引入
import 'codemirror/mode/javascript/javascript.js'
import 'codemirror/mode/css/css.js'
import 'codemirror/mode/xml/xml.js'
import 'codemirror/mode/clike/clike.js'
import 'codemirror/mode/markdown/markdown.js'
import 'codemirror/mode/python/python.js'
import 'codemirror/mode/r/r.js'
import 'codemirror/mode/shell/shell.js'
import 'codemirror/mode/sql/sql.js'
import 'codemirror/mode/swift/swift.js'
import 'codemirror/mode/vue/vue.js'

import { isIE11, isIE } from '@/utils/browser'

// 尝试获取全局实例
const CodeMirror = window.CodeMirror || _CodeMirror

export default {
  name: 'JCodeEditor',
  props: {
    // 外部传入的内容，用于实现双向绑定
    value: {
      type: String,
      default: ''
    },
    // 外部传入的语法类型
    language: {
      type: String,
      default: null
    },
    languageChange: {
      type: Boolean,
      default: false,
      required: false
    },
    placeholder: {
      type: String,
      default: null
    },
    // 显示行号
    lineNumbers: {
      type: Boolean,
      default: true
    },
    // 是否显示全屏按钮
    fullScreen: {
      type: Boolean,
      default: false
    },
    // 全屏以后的z-index
    zIndex: {
      type: [Number, String],
      default: 999
    },
    // 是否自适应高度，可以传String或Boolean
    // 传 String 类型只能写"!ie" ，
    // 填写这个字符串，代表其他浏览器自适应高度
    // 唯独IE下不自适应高度，因为IE下不支持min、max-height样式
    // 如果填写的不是"!ie"就视为true
    autoHeight: {
      type: [String, Boolean],
      default: true
    },
    // 不自适应高度的情况下生效的固定高度
    height: {
      type: [String, Number],
      default: '240px'
    }
  },
  data() {
    return {
      // 内部真实的内容
      code: '',
      iconType: 'fullscreen',
      hasCode: false,
      // 默认的语法类型
      mode: 'javascript',
      // 编辑器实例
      coder: null,
      // 默认配置
      options: {
        // 缩进格式
        tabSize: 2,
        // 主题，对应主题库 JS 需要提前引入
        theme: 'panda-syntax',
        line: true,
        // extraKeys: {'Ctrl': 'autocomplete'},//自定义快捷键
        hintOptions: {
          tables: {
            users: ['name', 'score', 'birthDate'],
            countries: ['name', 'population', 'size']
          }
        }
      },
      // 支持切换的语法高亮类型，对应 JS 已经提前引入
      // 使用的是 MIME-TYPE ，不过作为前缀的 text/ 在后面指定时写死了
      modes: [{
        value: 'css',
        label: 'CSS'
      }, {
        value: 'javascript',
        label: 'Javascript'
      }, {
        value: 'html',
        label: 'XML/HTML'
      }, {
        value: 'x-java',
        label: 'Java'
      }, {
        value: 'x-objectivec',
        label: 'Objective-C'
      }, {
        value: 'x-python',
        label: 'Python'
      }, {
        value: 'x-rsrc',
        label: 'R'
      }, {
        value: 'x-sh',
        label: 'Shell'
      }, {
        value: 'x-sql',
        label: 'SQL'
      }, {
        value: 'x-swift',
        label: 'Swift'
      }, {
        value: 'x-vue',
        label: 'Vue'
      }, {
        value: 'markdown',
        label: 'Markdown'
      }],
      // code 编辑器 是否全屏
      fullCoder: false
    }
  },
  watch: {
    fullCoder: {
      handler(value) {
        if (value) {
          this.iconType = 'fullscreen-exit'
        } else {
          this.iconType = 'fullscreen'
        }
      }
    },
    // value: {
    //   immediate: false,
    //   handler(value) {
    //     this._getCoder().then(() => {
    //       this.coder.setValue(value)
    //     })
    //   }
    // },
    language: {
      immediate: true,
      handler(language) {
        this._getCoder().then(() => {
          // 尝试从父容器获取语法类型
          if (language) {
            // 获取具体的语法类型对象
            let modeObj = this._getLanguage(language)

            // 判断父容器传入的语法是否被支持
            if (modeObj) {
              this.mode = modeObj.label
              this.coder.setOption('mode', `text/${modeObj.value}`)
            }
          }
        })
      }
    }
  },
  computed: {
    placeholderShow() {
      if (this.placeholder == null) {
        return `请在此输入${this.language}代码`
      } else {
        return this.placeholder
      }
    },
    nullTipStyle() {
      if (this.lineNumbers) {
        return { left: '36px' }
      } else {
        return { left: '12px' }
      }
    },
    // coder 配置
    coderOptions() {
      return {
        tabSize: this.options.tabSize,
        theme: this.options.theme,
        lineNumbers: this.lineNumbers,
        line: true,
        hintOptions: this.options.hintOptions
      }
    },
    isAutoHeight() {
      let { autoHeight } = this
      if (typeof autoHeight === 'string' && autoHeight.toLowerCase().trim() === '!ie') {
        autoHeight = !(isIE() || isIE11())
      } else {
        autoHeight = true
      }
      return autoHeight
    },
    fullScreenParentProps() {
      let props = {
        class: {
          'full-screen-parent': true,
          'full-screen': this.fullCoder,
          'auto-height': this.isAutoHeight
        },
        style: {}
      }
      if (isIE() || isIE11()) {
        props.style['height'] = '240px'
      }
      if (this.fullCoder) {
        props.style['z-index'] = this.zIndex
      }
      if (!this.isAutoHeight) {
        props.style['height'] = (typeof this.height === 'number' ? this.height + 'px' : this.height)
      }
      return props
    }
  },
  mounted() {
    // 初始化
    this._initialize()
  },
  methods: {
    // 初始化
    _initialize() {
      // 初始化编辑器实例，传入需要被实例化的文本域对象和默认配置
      this.coder = CodeMirror.fromTextArea(this.$refs.textarea, this.coderOptions)
      // 编辑器赋值
      if (this.value || this.code) {
        this.hasCode = true
        //this.coder.setValue(this.value || this.code)
        this.setCodeContent(this.value || this.code)
      } else {
        this.coder.setValue('')
        this.hasCode = false
      }
      // 支持双向绑定
      this.coder.on('change', (coder) => {
        this.code = coder.getValue()
        if (this.code) {
          this.hasCode = true
        } else {
          this.hasCode = false
        }
        if (this.$emit) {
          this.$emit('input', this.code)
        }
      })
      this.coder.on('focus', () => {
        this.hasCode = true
      })
      this.coder.on('blur', () => {
        if (this.code) {
          this.hasCode = true
        } else {
          this.hasCode = false
        }
      })

      /* this.coder.on('cursorActivity',()=>{
         this.coder.showHint()
       })*/

    },
    getCodeContent() {
      return this.code
    },
    setCodeContent(val) {
      setTimeout(() => {
        if (!val) {
          this.coder.setValue('')
        } else {
          this.coder.setValue(val)
        }
      }, 300)
    },
    // 获取当前语法类型
    _getLanguage(language) {
      // 在支持的语法类型列表中寻找传入的语法类型
      return this.modes.find((mode) => {
        // 所有的值都忽略大小写，方便比较
        let currentLanguage = language.toLowerCase()
        let currentLabel = mode.label.toLowerCase()
        let currentValue = mode.value.toLowerCase()

        // 由于真实值可能不规范，例如 java 的真实值是 x-java ，所以讲 value 和 label 同时和传入语法进行比较
        return currentLabel === currentLanguage || currentValue === currentLanguage
      })
    },
    _getCoder() {
      let _this = this
      return new Promise((resolve) => {
        (function get() {
          if (_this.coder) {
            resolve(_this.coder)
          } else {
            setTimeout(get, 10)
          }
        })()
      })
    },
    // 更改模式
    changeMode(val) {
      // 修改编辑器的语法配置
      this.coder.setOption('mode', `text/${val}`)

      // 获取修改后的语法
      let label = this._getLanguage(val).label.toLowerCase()

      // 允许父容器通过以下函数监听当前的语法值
      this.$emit('language-change', label)
    },
    nullTipClick() {
      this.coder.focus()
    }
  }
}
</script>

<style lang="less">
.code-editor-cust {
  flex-grow: 1;
  display: flex;
  position: relative;
  height: 100%;

  .CodeMirror {
    flex-grow: 1;
    z-index: 1;

    .CodeMirror-code {
      line-height: 19px;
    }

  }

  .code-mode-select {
    position: absolute;
    z-index: 2;
    right: 10px;
    top: 10px;
    max-width: 130px;
  }

  .CodeMirror {
    height: auto;
    min-height: 100%;
  }

  .null-tip {
    position: absolute;
    top: 4px;
    left: 36px;
    z-index: 10;
    color: #ffffffc9;
    line-height: initial;
  }

  .null-tip-hidden {
    display: none;
  }

  /**选中样式偶然出现高度不够的情况*/

  .CodeMirror-selected {
    min-height: 19px !important;
  }
}

/* 全屏样式 */
.full-screen-parent {
  position: relative;

  .full-screen-icon {
    opacity: 0;
    color: black;
    width: 20px;
    height: 20px;
    line-height: 24px;
    background-color: white;
    position: absolute;
    top: 2px;
    right: 2px;
    z-index: 9;
    cursor: pointer;
    transition: opacity 0.3s;
  }

  &:hover {
    .full-screen-icon {
      opacity: 1;

      &:hover {
        background-color: rgba(255, 255, 255, 0.88);
      }
    }
  }

  &.full-screen {
    position: fixed;
    top: 10px;
    left: 10px;
    width: calc(100% - 20px);
    height: calc(100% - 20px);
    padding: 10px;
    background-color: #f5f5f5;

    .full-screen-icon {
      top: 12px;
      right: 12px;
    }

    .full-screen-child {
      height: 100%;
      max-height: 100%;
      min-height: 100%;
    }
  }

  .full-screen-child {
    height: 100%;
  }

  &.auto-height {
    .full-screen-child {
      min-height: 120px;
      max-height: 320px;
      height: unset;
      overflow: hidden;
    }

    &.full-screen .full-screen-child {
      height: 100%;
      max-height: 100%;
      min-height: 100%;
    }
  }

}

.CodeMirror-cursor {
  height: 18.4px !important;
}
</style>